[PATCH] sunrpc: initialize delayed work on each rpc_inode allocation

[Jeff Layton <jlayton@redhat.com>]

The debugobjects code will sometimes pop a warning like this when the
queue_timeout job is queued to a workqueue:

[ 5157.128514] WARNING: at lib/debugobjects.c:262 debug_print_object+0x8c/0xb0()
[ 5157.128742] Hardware name: Bochs
[ 5157.128742] ODEBUG: activate not available (active state 0) object type: timer_list hint: stub_timer+0x0/0x20
[ 5157.128742] Modules linked in: nfsd(O) nfs_acl auth_rpcgss lockd sunrpc floppy virtio_net i2c_piix4 i2c_core virtio_balloon joydev pcspkr virtio_blk [last unloaded: nfsd]
[ 5157.128742] Pid: 1312, comm: rpc.nfsd Tainted: G        W  O 3.3.0-rc1+ #1
[ 5157.128742] Call Trace:
[ 5157.128742]  [<ffffffff8106135f>] warn_slowpath_common+0x7f/0xc0
[ 5157.128742]  [<ffffffff81061456>] warn_slowpath_fmt+0x46/0x50
[ 5157.128742]  [<ffffffff8132ba2c>] debug_print_object+0x8c/0xb0
[ 5157.128742]  [<ffffffff81070db0>] ? timer_debug_hint+0x10/0x10
[ 5157.128742]  [<ffffffff8132c02b>] debug_object_activate+0xfb/0x190
[ 5157.128742]  [<ffffffff81072728>] ? lock_timer_base.isra.24+0x38/0x70
[ 5157.128742]  [<ffffffff81074676>] mod_timer+0xf6/0x450
[ 5157.128742]  [<ffffffff810749e8>] add_timer+0x18/0x20
[ 5157.128742]  [<ffffffff8108168e>] queue_delayed_work_on+0xbe/0x140
[ 5157.128742]  [<ffffffff81084441>] queue_delayed_work+0x21/0x40
[ 5157.128742]  [<ffffffffa006e568>] rpc_queue_upcall+0xe8/0x100 [sunrpc]
[ 5157.128742]  [<ffffffffa012a121>] __cld_pipe_upcall+0x61/0xc0 [nfsd]
[ 5157.128742]  [<ffffffffa012ad98>] nfsd4_cld_init+0x48/0x140 [nfsd]
[ 5157.128742]  [<ffffffffa012b22a>] nfsd4_client_tracking_init+0x2a/0xc0 [nfsd]
[ 5157.128742]  [<ffffffff8169797e>] ? mutex_unlock+0xe/0x10
[ 5157.128742]  [<ffffffffa01266fa>] nfs4_state_start+0x1a/0x100 [nfsd]
[ 5157.128742]  [<ffffffffa01028c5>] nfsd_svc+0x135/0x200 [nfsd]
[ 5157.128742]  [<ffffffffa0103df0>] ? write_maxblksize+0x130/0x130 [nfsd]
[ 5157.128742]  [<ffffffffa0103e6d>] write_threads+0x7d/0xd0 [nfsd]
[ 5157.128742]  [<ffffffff811dd16a>] ? simple_transaction_get+0xca/0xe0
[ 5157.128742]  [<ffffffffa0102ee7>] nfsctl_transaction_write+0x57/0x90 [nfsd]
[ 5157.128742]  [<ffffffff811b4c9f>] vfs_write+0xaf/0x190
[ 5157.128742]  [<ffffffff811b4fdd>] sys_write+0x4d/0x90
[ 5157.128742]  [<ffffffff816a3469>] system_call_fastpath+0x16/0x1b

This occurs when an rpc_inode object is recycled. The slab constructor
routine doesn't necessarily get called on it again, so the debugobjects
code isn't aware that it's already initialized.

Work around this problem by initializing the delayed work every time
an inode is allocated out of the slab, not just when a new slab is.

Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 net/sunrpc/rpc_pipe.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 63a7a7a..58e1dd1 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -178,6 +178,8 @@ rpc_alloc_inode(struct super_block *sb)
 	rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 	if (!rpci)
 		return NULL;
+
+	INIT_DELAYED_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue);
 	return &rpci->vfs_inode;
 }
 
@@ -1073,8 +1075,6 @@ init_once(void *foo)
 	INIT_LIST_HEAD(&rpci->pipe);
 	rpci->pipelen = 0;
 	init_waitqueue_head(&rpci->waitq);
-	INIT_DELAYED_WORK(&rpci->queue_timeout,
-			    rpc_timeout_upcall_queue);
 	rpci->ops = NULL;
 }
 
-- 
1.7.7.5